Tool supporting and guiding apparatus



Aug. 25, 19 42. V J, H. RQUNTREE 2,293,853

TOOL SUPPORTING AND GUIDING APPARATUS 'Fmdua a, 1939- I :5 Siie'ets-Sheet 1 9 JOHN H.- ROUNTREE 4O v BY A ATTORNEY Aug 25, 1942, .1.H. RQUNTREE I TOOL SUPPORTING AND GUIDING APPARATUS INVENTOR JOHN H.ROUNTREE ATTORNEY Patented Aug. 25, 1942 TOOL SUPPORTING AND GUIDINGarram'ros John H. Ronni-rec, Elizabeth, N. 1., assignor to The Linda AirProducts Company, a corporation of Ohio Application May a, 1939, SerialNo. 271,415

16 Claims.

This invention relates to tool supporting and guiding apparatus and moreparticularly to plate riding devices adapted to propel flame-severingand flame-beveling blow-pipes along and in uniform spaced relation to awork surface.

Steel plates and other structural members as furnished by steel millsoften are not absolutely flat, but have undulations and otherirregularities in the surface of the metal which remain, even when themetal is laid upon a flat support. It is often desirable to propel ablowpipe or other tool along such a metal surface and to maintain thetool in uniform relation thereto. The present invention is specificallydirected to means for applying one or more flame-cutting Jets, as forexample, flame-severing or flame-beveling Jets,

"along a predetermined path with respect to a relatively large steelplate or similar work surface. J

Large steel plates, 'of the character mentioned, may have a deviationfrom flatness as much as substantially two inches without departing fromstandard specifications, which deviation may increase considerablyduring a flame-cutting or similar process as. a result of furtherdistortion produced by stresses during heating. Ordinarily, when cuttinglarge plates, use is made of a carriage which is supported and propelledalong a level track or template simulating the path to be followed bythe blov'pipe. An armor other supporting means secured to the carriagemaintains adjoining relation to a similar edge for the deposit of weldmetal. A process for performing such successive cutting operations, forexample, flame severing and trimming or flame severing and beveling isdisclosed in Patent 2,184,562, dated December 26, 1939. When performingthese operations, the slightest variation of the blowpipe holdertransversely of the path in either a vertical or sidewise direction,produces a corresponding change in the shape of the edge being formed.If such changes exceed narrow limits,

the edges no longer abut properly for an ensuing welding operation.

Accordingly, the principal objects of the present invention are toprovide tool-supporting and guiding apparatus overcoming the defectspreviously enumerated; to provide a novelblowpipesupporting frame withimproved means for securing the frame to a propelling carriage so thatthe frame may ride or float at a constant distance above the worksurface; to provide means for swiveling a blowpipe-supporting frame withrespect to the propelling carriage; to provide improved wheel supportingmeans for maintaining the blowpipe-supporting frame at a uniformdistance above the work surface; to provide improved'cutting headspecifically adapted to project a plurality of cutting jets; and toprovide means whereby the cutting heads may be adjustably positioned andmaintained in predetermined the blowpipe or other tool-in operativerelation to the metal plate or other work surface and imparts the motionof the carriage to the blowpipe means or other tool. It is apparent thatif a blowpipe or other tool is passed over the surface of such anirregular plate while being rigidly secured to an independentlysupported carriage, the vertical spacing between the metal plate and thetool would vary in accord with the irreguthe Jet must be maintainedwithin relatively 50 normal relation with respect to a work surface.These and other objects of the present invention will become morereadily" apparent from the fol-- lowing description andfrorn theaccompanying drawings disclosing several forms of apparatus smalltolerances, for example, tolerances withinand trimmed or beveledsuccessively to form a straight scarfed edge adapted to be disposed in 5embodying principles of the invention. In the drawings; U

Fig. 1 is a perspective view of one form of apparatus incorporatingprinciples of the present invention and comprising a plate-riding deviceadapted to support flame-severing and flame-beveling blowpipes;

Fig. 2 is a side elevational view of the apparatus disclosed in Fig. 1;

Figs. 3, 4, and 5 areelevational views of a modified form ofconstruction;

Fig. 6 1s a vertical cross-sectional view of a cutting head adapted tobe employed with the improved plate-riding device, and

Fig. "I is a detailed elevationalview of a modified form of wheelsupport for the blowpipe undercarriage.

Although the invention may top-plan, rear, and side be adapted'tosupport various types of tools such as, for example,

scribers, crayons, gouging implements, and the like, the invention, forconvenience, has been illustrated herein in conjunction with blowpipemeans adapted to project one or more gaseous jets upon a work surface.Although welding blowpipes may be used, the invention is disclosed inconnection with cutting blowpipes adapted to project a series of cuttingjets, for example, of the type adapted to form square and/or bevelededges in a ferrous metal plate.

With particular reference to Fig. l, the invention broadly comprises acarriage adapted to be supported and propelled along a predeterminedpath as, for example, rails R. An arm or support A is rigidly secured tothe carriage C and extends outwardly over a work surface S. Ablowpipe-supporting frame or undercarriage U floats or rides along thesurface S, the undercarriage being supported by wheel means W in rollingengagement with the work surface. Blowpipe means B secured to theundercarriage U may thus be maintained at a uniform distance above thework surface S, being free to rise and fall in accord withirregularities in the work surface. The longitudinal motion of thecarriage C is imparted to the undercarriage U by means of links L whichmaintain the undercarriage against sidewise displacement whilepermitting vertical motion of the undercarriage relative to the carriageC and arm A. Various modifications of this general combination aredisclosed throughout the application and will become apparent from thfollowing detailed description.

In Figs. 1 and 2, one form of apparatus incorporating principles of theinvention comprises the self-propelled carriage C, consisting generallyof a light-weight portable machine II, for example, of the typedisclosed in Patent No. 2,- 183,605, which was granted on December 19,1939. The machine II is provided with a. superto the machine II as bymeans of a slideway 13. The arm A extends outwardly from the carriage Cas a cantilever beam, being sufficiently strong and rigid to secure thefloating blowpipe-supporting frame U against undesirable sidewisemovement with respect to the work surface S. A counterweight l4 may beprovided, if necessary, to counterbalance the arm A and the weight ofthe structure supported thereby. A lug l5 provides means whereby theentire apparatus may belifted and transported from one location toanother as by means of a crane. Although any form of carriage may beemployed for supporting the arm A in overhanging relation .to the worksurface S, the herein disclosed machine II is specifically adapted formotion along straight or substantially straight lines and accordingly isprovided with a pair of rails R comprising the flanges of a standard Ibeam, which is supported in a level position adjacent to the worksurface in any convenient manner.

The tool support or undercarriage U is herein disclosed as a generallyhorizontal platform or frame adapted to support blowpipe means 13comprising, for example, a severing blowpipe l6 and a bevel-cuttingblowpipe H. In the form of construction disclosed in Figs. 1 and 2, the

blowpipe-supporting frame comprises a platform ment with respect to thearm A without sidewise displacement as the platform rises and falls inaccord with irregularities in the work surface. As indicated in Figs. 1and 2, such supporting means comprises link means L preferablyconsisting of three separate links 2| extending in parallel relationshipbetween the arm A and the platform 20. The arm A is provided with anequal number of clevises 22, 23, and 24, preferably located in ahorizontal plane. One clevis 22 is positioned adjacent to one side ofthe arm A, for example, the leading edge, and desirably at anintermediate point along the length of the arm. Clevises 23 and 24 arelocated adjacent to the opposite side of the arm, for example, thetrailing edge, at points spaced along the length of the arm, forexample, at points equally spaced from the clevis 22. The links 2! arepivotally secured at one end to the respective clevises 22, 23, and 24,and extend in a parallel relation therefrom, preferably in a downwardand rearward direction, for pivotal connection at the lower end with theplatform 20. A clevis pin 25 extends between the arms of each clevis,two of the pins being in the same straight line and the third beingparallel to them. Each pin forms a closefitting journal on which theupper end of each of the links is mounted. As shown in Fig. l, the linksdepending from clevises 23 and 24 may be journalled directly to themember I8, and a suitable yoke 26 may be provided at the forward end ofthe member l9 to receive the link 2| extending from the clevis 22.

A load-sustaining rod 21 is pivoted at its lower end to the platform 20,while the upper end extends through an aperture 28 formed in anextension of thearm A. A compression spring 29 is held on the rod 21 soas to exert a lifting force structure I2 transversely adjustable withrespect on the undercarriage U, thus removing some of the weight of theundercarriage from the work surface S. The spring 29 further providesfor more gentle lowering of the undercarriage, for example, when thedevice passes over the end of the work surface.

Some form of surface-engaging means is provided to maintain the platformand its associated tool or tools at a uniform distance from the worksurface. For this purpose, use is preferably made of wheel means adaptedto support the platform 20 in rolling engagement with the work surface.As shown in Figs. 1 and 2, the apparatus disclosed comprises awheel-mounting yoke 3|, the upwardly extending arms 32 of which connectin any convenient manner with the platform 2|]. Spacer blocks 33 may beinterposed between the yoke 3| and the point of attachment on theplatform 20. Other equivalent construction may be provided to permittransverse adjustment of the yoke 3i with respect to the plaform 20, inorder to permit laterally positioning the wheels, as close as possibleto the bevel-cutting or similar blowpipe ll. The lower horizontalportion 40 of the yoke is slotted to receive one or more wheels 34, theposition of which may be adjusted with respect to the slot. The purposeof providing means for adjusting the position of the wheels inlongitudinal and transverse directions is to enable the rolling supportto engage the work surface at a point as close as convenientlypossibleto the delivery end of the blowpipes.

Suitable clamps 35 and 36 are provided for securing the respectiveblowpipes l6 and I! in position on the platform 20, which clampspreferably are adjustably positioned upon the members i8 and H to shiftthe blowpipes selectively in a horizontal plane. The clamps are ofconventional design, such as permit swiveling motion and pivotal motionof the blowpipes about one Or more axes so as to permit adjusting theblowpipes to any desired position. The clamp 36 comprises a body portion31 rigidly clamped to the member |8 and a telescoping portion 38,'se-

comprises a bolt 41, adjustable with respect to the support 45 bymovement within a slot 48.

cured to the blowpipe and adjustable along the member l8 as by means ofan adjustment screw 39, threaded to the portion 31, as shown in Fig. 1.After initially securing the portion 31 in its approximate position, thesize of the bevel to be cut by the blowpipe |1 may b adjusted accuratelyby means of the transverse adjustment screw 39. square-cutting blowpipeI for an adjustable clamp 36 of the type shown in connection with thebeveling blowpipe l1, such a clamp may be used if desired.

It will be observed from the foregoing description that the constructionprovides a very Although there is lessneed on the One or moreload-sustaining rods 21, provided with compression springs 29', assistin supporting the platform and in avoiding unnecessary shock to theparts of the undercarriage U as y when the wheel 34 rolls ofi the-end ofthe work.

surface S. The bearing 4| permits 180" rotation of the undercarriageafter one pass, to position the parts for a return pass along an ad- Yjoining plate, or along another side of the sam plate.

It will be noted that the links 2| are relatively compactly located andthat the arm A is considerably shorter than the arm A disclosed in Figs.1 and 2. The resulting saving in space is more fully utilized by the useof an improved type of cutting head H which may be secured dirigidsupport for the blowpipe means so far as lateral or sidewise motion isconcerned, but at the same time permits free movement of theundercarriage in a vertical plane. Rigidity is enhanced by disposing thethree clevises 22, 23, and 24-, in a horizontal plane. The links arewidely spaced and are accurately fitted within their respective pivotalmountings so as to minimize lost motion. The wheel support is rigidlymounted to the platform 20, and much of the weight of the undercarriageis absorbed by the spring 21, thus enhancing the freedom of motion ofthe undercarriage as it floats or rides on the work surface S. Theprecision of a straight cut is dependent largely upon the accuracy'withwhich the sections of the rails R may be assembled toform a longstraight path, and not rectly to the discharge end of a conventionalcutting blowpipe. One such form of improved cuthead which is disclosedin Figs. 6 and '7, comprises a casing 49 having connecting means 5|secured to the discharge end of a cutting blowf The oxidizing cuttinggas passes through a central conduit52 in the connecting means 5|, whichconduit compipe B as by a coupling nut 50.

municates with a, manifold 53 adapted to distribute the cutting gas to aplurality of nozzlereceiving cavities 54. A preheating-gas conduit 55extends through the connecting means 5| and communicates with a manifoldadapted to distribute preheating mixture from the blowpipe to therespective cavities 54. A plurality of inclined generally parallelnozzles 51 and 58 are mounted within the respective cavities 54 in fluidcommunication with the supply of cutting oxygen and preheating mixture.

- The cutting head H disclosed in F g. W Doupon side motion in theundercarriage. This is overcome largely by using a single long I-beamwhere possible.

A modified form of apparatus embodying features of the present inventionis disclosed in Figs. 3, 4, and 5 wherein parts corresponding with thosedescribed in connection with Figs, 1 and 2 are designated by likereference characters. The carriage C comprises a self-propelled machinesupported for rolling engagement 4 with rails R. as shown in Fig. 4. Anarm A'- is rigidly secured to the superstructure of the carriage in amanner similarto.-that described in connection with Figs. 1 and 2. Thearm A ter- 'minates in avertically disposed bearing or clamp 4| forswivelly receiving a tubular spindle 42 extending upwardly from alink-supporting plate 43; A collar 44 is rigidly secured to the top ofthe spindle 42 to prevent the plate 43 and spinr dle 42 from fallingfrom the clamp 4| when in horizontal'position by means of the links2|'.'

The platform 20' is supported with respect to the work surface by meansof a single relatively large wheel 34' which may be adjustablypositioned upon a wheel support 46 extending downwardly from theplatform 20'. The wheel axle siti'oned so that the nozzles are inclinedin the direction of travel, may be employed for obtaining high-speedcutting in the manner disclosed .in the previously mentioned Patent2,184,562.

The cutting jet from the leading nozzle 51 forms a severing cut throughthe metal body, while the irregular edges of the kerf are trimmed orsmoothed by the cutting jet issuing from the nozzle 58, which latternozzle is preferably offset a slight degree in a lateral directionfromthe leading nozzle 51. By means of a cutting head H of the typeshown in Fig. 6, a considerable saving in space is efiected and therespective jets can be manipulated and controlled with considerably moreease than can a plurality of separate blowpipes.v

Although the cutting head shown in Fig. 6 is specifically adapted for aflame-cutting and trimming operation; the same design principles may beincorporated in a similar cutting head H adapted to perform a cuttingand beveling operation. Fig. 4 discloses such a head-wherein use is madeof a casing 49' having connecting means 5| of the type shown in Fig. 6for securing the'head H to the discharge end of a cutting blowpipe B.The internal connections and conduits are identical-with those-shown inFig. 6,

with the exception that the nozzles are disposed in a slightly difierentfashion. Use is preferably made of a leading nozzle 51, the axis ofwhich 7 is substantially parallel to that of the connecting means SI andto the axis of the blowpipe B", so that when the blowpipe B' is disposedin a ver tical position, the nozzle 51' is adapted to form the squaringofi or vertical face of a beveled edge. A trailing nozzle 58' isdisposedman inclined position, sloping downwardly in a forward 56 which is and alateral direction so as to form the inclined face of the undercutbeveled edge. As shown in Fig. 5, the nozzle 58' is so inclined andspaced from the nozzle 51 that the jets issuing from the respectivenozzles will not intersect. The use of a bevel-cutting head or adaptorH, as shown in Figs. 4 and 5, permits the wheel 34' to be locateddirectly adjacent to both nozzles, thus assisting in maintaining thenozzles precisely in uniform spaced relation to the work surface S.Furthermore, by employing a wheel 34' of fairly large diameter, it ispossible to locate the spaced nozzles 51 and 58 so that all portionsthereof,

and especially the discharge ends, are located within the axiallyprojected circumference of the wheel. In this manner the wheel peripheryoffers a large degree of protection to the nozzles, saving them fromundesirable contact with the work surface, for example, at the start orend of a cutting operation.

The blowpipe B shown in Figs. 3, 4, and 5, projects vertically throughthe platform 20' being secured firmly with respect thereto by means ofan adjustable mounting 59. The mounting 59 comprises a tubular body 6|fitted with conventional blowpipe elevating mechanism 62 adapted toengage a rack 63 extending longitudinally of the blowpipe B. A flange 64rests against the platform 20' and is provided with a plurality ofcircular slots 65 through which project machine screws or similarfastening means 56. By loosening the screws 66, the blowpipe B and themounting 59 may be adjustably swiveled and held in any desired positionso as to align the cutting head H accurately with respect to the edge tobe formed without disturbing the coupling nut 60. Suitable indicia 61may be provided on the flange 64 as shown in Fig. 4, to permit accurateadjustment of the parts. By swiveling the blowpipe B' about its axis,the head H is rotated, effecting a change in the depth of the bevel faceat the normal spacing of the nozzles above the work. Accordingly,

it is possible to out various depths of angular shape of the bevel bothby varying the angle of the bevel face, and the depth of the verticalface or nose. Swiveling of the'cutting head H does not affect the angleof the jet forming the vertical face of the scarfed edge, because thenozzle 51 is parallel to the axis about which the blowpipe is swiveled.

A modified form of wheel-supporting means is disclosed in Fig. 7. Acaster 58, comprising a wheel 69 and clevis H, is pivotally mounted to aportion of the undercarriage U, as for example, to theblowpipe-supporting frame disclosed in either Fig. 1 or 5. A pint1e'12extending up-' wardly from the clevis II is mounted to turn freely abouta vertical axis as by means of a ball bearing I3 housed within a support14 which, in turn, is secured in a suitable manner to the platform 20'of the undercarriage U. The clevis H is provided with a slot 15 toadjustably receive the axle 18 ofthe wheel 69. By shifting the caster tothe leading position at the start of 'a cutting operation, as shown byfull lines in Fig. '7, the point of rolling contact between the wheel 69and the work surface S is located forward of the cutting nozzles 51 and58. thus providing for proper positioning of the nozzles with respect tothe initial edge of the work surface. Throughout the cutting operationthe point .of rolling contact is either directly ad jacent to thenozzles or slightly behind them, so that full support is provided forthe nozzles right up to the final stage of the cutting.

Since the wheel 69 preferably is located closely adjacent to the head Hin the operating position, it is desirable, when the caster pivots fromthe leading position to the trailing position, that it move in anarcuate path away from the nozzles so as not to abut against the head H.This is effected by the use of a stop 11 depending from the support 14,and a pin 18 extending from the clevis II adapted to abut against thestop 11 to prevent the caster from swiveling in the direction of thecutting head H. Preferably the stop ll is located so as to maintain thecaster 58 slightly to one side of the dead center position,

so that as the apparatus is set in motion the caster is urged to pivotin an arcuate path away from the head H. A second stop I9 may be locatedopposite the stop 11 to prevent the caster from being moved against thehead H when the caster is in the trailing position, slight clearancenormally being provided between the pin I8 and the stop 19.

By providing slightly greater spacing in a transverse direction betweenthe blowpipe means and the caster 68, the stops l1 and 19 may beeliminated thereby allowing thecaster to swivel through a complete orsubstantially complete circle. Such an arrangement in conjunction withthe pivotal mounting means between the carriage and undercarriage asshown in Fig. 5, provides for allowing the cutting head to followslightly irregular paths of predetermined contour even though thecarriage C is propelled along a straight line. Under these conditionsthe blowpipe means is maintained at a constant height above the worksurface even though the path to be followed is an irregular contour.

As shown in Fig. 4, the nozzles 51' and 58' are located close enoughtogether. transversely of the line of cut, that the nozzle 51' forms thevertical face at the top portion of the edge, while the nozzle 58 formsan undercut bevel face at the bottom-portion of theedge. By providinggreater spacing between the two nozzles, or us ing the present nozzle ona thinner plate the nozzle 58' may form a top bevel face on theadjoining section of metal, while the nozzle 51' forms the usualrelatively small vertical face at the bottom portion of the sameadjoining section.

Various other modifications of the invention may be made withoutdeparting from the scope of the invention or sacrificing its advantages.

I claim: 1

1. Apparatus for supporting and guiding a blowpipe comprising an armadapted to be detachably connected to a movable carriage, said arm beingmovable by said carriage above a generally horizontal work surface alongadesired path of travel, said arm extending in a generally horizontaldirection transversely of said path of travel; a blowpipe-supportingplatform located substantially horizontally beneath said arm; pivotallinks extending between said horizontal platform and said arm adapted tomaintain said plat-.

form horizontal during relative vertical movement between said arm andsaid platform; surface-engaging means depending from said platform formaintaining said platform at a uniform distance from said work surface;and blowpipe mounting means adjustably supported on said platform andbeing adapted to shift the position of the discharge portion of saidblowpipe along said horizontal platform.

2. Apparatus as claimed in claim 1 wherein said arm comprises acantilever and wherein said links are located in spaced relation alongsaid arm.

3. Blowpipe supporting and guiding apparatus comprising a carriage;means for propelling said carriage along a predetermined path; ahorizontal arm extending from said carriage over a work surface; aplatform extending longitudinally and transversely of said path in ahorizontal plane below said arm; blowpipe supporting means .adiustablymounted on said. platform; a link pivotally secured at one end to oneside of said arm at an intermediate point along the length of said armand pivotally secured at its other end to said platform; a pair ofspaced links pivotally secured adjacent to the opposite side of said armat points spaced along the length thereof, said links extending parallelto said first mentioned link and having their opposite ends secured tosaid platform, said links being pivotally connected to said arm atpoints forming the apices of a substantially equilateral triangle; andmeans depending from said platform and adapted to engage said surface toraise and lower said platform in accord with irregularities in saidsurface to maintain said platform at a uniform distance from saidsurface.

4. Apparatus for supporting and guiding metal severing and bevelingblowpipes, comprising a carriage adapted to be propelled along a path;an arm projecting from said carriage over a work surface; ablowpipe-supporting frame comprising a first member extendingsubstantially parallel with said arm, and a second member secured to andextending horizontally substantially at right angles from said firstmember; links pivotally secured adiacent'to the free ends of saidmembers,

said links extending in parallel relation from said spect to said frame.

6. Apparatus as claimed in claim 4 wherein such depending meanscomprises a support; a plurality of wheels rotatably mounted on saidsupport upon parallel spaced axes; and means for adjustably positioningsaid wheels on said 8. Apparatus for supporting and guiding a blowpipe,comprising an arm adapted to be connected at one end to a self-propelledcarriage, said arm being movable by said carriage above a generallyhorizontal worksurface along a desired path of travel, said armextending in a generally parallel equal-length links pivotallyconnecting said member and said platform about axes located respectivelyin spaced parallelv planes to maintain said platform in a horizontalplane during relative vertical movement between said platform and saidmember. and a wheel adapted to roll on said work surface and to supportsaid platform-in uniform spaced relation to said work surface, saidundercarriage being. free to swivel completely arm.

9. Apparatus as claimed in claim 8 including locking means adapted tolock said undercarriage in predetermined swiveled relation to said arm.

- 10. In a plate riding device having a floating blowpipe-supportingframe, and means for propelling said frame relatively to a path over thethat the point of rolling contact of said caster whereby said caster'maysupport said frame I when said nozzle is initially located over an edgeof said surface, said axis being so located that said point of rollingcontact is directly adjacent support to vary the location of said wheelswith respect to such blowpipe-attaching means.

'7. Apparatus as claimedin claim 4 wherein such depending meanscomprises'a yoke, said yoke having arms secured at the top portion tosaid frame; wheels vrotatably mounted on said yoke with parallel spacedaxes; and means for securing at least one of said wheels in adjustablespaced relation to said yoke.

to said nozzle when said caster pivots to a trailing position duringforward movement of said frame relative to said path.

11. In a plate riding device having a floating blowpipe-supportingframe, and means for propelling said frame relatively to a path over thetop surface of a metal body, the combination comprising means forsecuring blowpipe means on said frame in position to project a gaseouslet against said surface from at least one nozzle on said blowpipemeans; wheel means secured to said frame for rolling engagement withsaid surface to maintain the discharge portion of said nozzle at auniform distance from said surface,

said wheel means comprising a. caster pivotal in an orbit about avertical axis, said axis being so located with respect to said blowpipemeans that the point of rolling contact of said caster on said a surfaceis located substantially forward of said nozzle when said caster isinthe leading position, and adjacent to said nozzle when said caster is inthe trailing position; and stop means adapted to locate said caster awayfrom a dead-center position, thereby causing said caster to swivel from'the leading position to the trailing position in an arcuate pathextending in such a direction as to preclude interference withsaidnozzle.

about a vertical axis beneath said.

-top' surface of a metal body, the combination comprising means forsecuring a blowpipe means 12. Metal-cutting apparatus comprising, incombination, a plate-riding device including a vertically floatingblowpipe-supporting platform comprising a plate disposed in asubstantially horizontal plane; a carriage for propelling said platformalong a path over a surface of a metal body; parallel equal-length linkspivotally connecting said carriage with said platform, said links beingpivoted about axes spaced longitudinally of said path, said axes beinglocated respectively in substantially horizontal planes so as tomaintain said platform in a horizontal position during relative verticalmovement between said platform and said carriage; a blowpipe adjustablypositioned on said platform and extending down-. ward toward saidsurface; a cutting head secured to the discharge end of saidblowpipe,'said cutand cutting oxygen from said connecting means to saidnozzles.

15. A flame-cutting-and-beveling head movable by a support along apredetermined path on the horizontal surface of a workpiece comprising acasing; connecting means adapted to I secure said casing to thedischarge end of a verting head being provided with a, plurality ofspaced cutting nozzles adapted to direct flamecutting jets against saidsurface at spaced points along the line of cut; and at least one wheeldepending from said platform and adapted to support said floatingplatform in rolling engagement with said surface, to maintain saidnozzles in uniform spaced relation to said surface.

13. Metal-cutting apparatus as claimed in claim 12, wherein one of saidcutting nozzles is a vertical severing nozzle, and the other of saidcutting nozzles is an inclined beveling nozzle in non-intersectingrelation to said vertical severing nozzle; and including means forvarying the shape of the bevel formed with said beveling nozzle,comprising a swiveled connection between said blowpipe and said platformadapted to provide pivotal movement of said blowpipe about its axis, tothereby adjust the angle and spacing of saidbeveling nozzle to the lineof cut, and accordingly the shape of the bevel formed by said bevelingnozzle.

14. A flame-cutting head adapted to be advanced along a path on a worksurface comprising a casing; connecting means for securing said casingto the discharge end of a cutting blowpipe, said casing being providedwith a plurality of spaced nozzle seating means in tandem along saidpath having axes inclined relative to said connecting means in closelyadjoining laterallyspaced substantially yertical planes; nozzles se=cured to said seating means and adapted to project flame-severing andtrimming jets respectively in tandem relation in a forwardly-inclineddirection along said path; and conduits within said casing adapted toconduct preheating mixture tically disposed cutting blowpipe mounted onsaid support; a plurality of spaced nozzles pro- ,jecting from saidcasing. at least one of said nozzles being adapted to deliver a firstjet substantially parallel with the axis of said blowpipe to form avertical edge on a workpiece, and another of said nozzles being adaptedto deliver a second jet inclined toward but in non-intersecting relationto said first jet to form a beveled edge on said workpiece;. andconduits extending through said connecting means to said nozzles, toprovide said nozzles with flame-cutting gases from the discharge end ofsaid blowpipe, said head being adjustable relative to said support abouta vertical axis offset from both of said nozzles to control the shape ofsuch beveled edge and the location of said vertical edge according tothe pivotal position of said head relative to said support.

I6. Flame cutting and beveling apparatus adapted to be propelled along apath of travel on the surface of a ferrous metal workpiece, comprising ahead having seats adapted to receive a pair of cutting nozzles extendingin fixed spaced relation from said head, and having inlet means adaptedto connect said nozzles with sources of cutting oxygen and combustiblepreheating gas respectively; a first of said nozzles being adapted whenin operating positionv to project a jet of cutting oxygenperpendicularly against said plate, the second of said nozzles beinginclined relatively to said first nozzle and being adapted to project asecond jet of cutting oxygen toward but in non-intersecting relation tosaid first-men-

